Liquid crystal display devices are being used for timepieces, electronic calculators, various measurement instruments, automobile panels, word processors, electronic diaries, printers, computers, televisions, timepieces, advertising display boards, and the like. The liquid crystal display modes typically include a Twisted Nematic (TN) mode, a Super-Twisted Nematic (STN) mode, a vertical alignment mode using a Thin Transistor Film (TFT), In-Plane Switching (IPN) mode, and the like. A Liquid crystal composition used for these liquid crystal display devices is required to be stable with respect to external stimulation such as moisture, air, heat, and light, forms a liquid crystal phase in the widest possible temperature range with room temperature as a center of the range, and has a low viscosity and a low driving voltage. Moreover, the liquid crystal composition is constituted with several to dozens of types of compounds to yield optimal values of a dielectric anisotropy (Δ∈), a refractive index anisotropy (Δn), and the like in each of the display devices.
In the Vertical Alignment (VA) display mode, a liquid crystal composition showing negative Δ∈ is used, and in a horizontal alignment display mode such as the TN mode, STN mode, or In-Plane Switching (IPS) mode, a liquid crystal composition showing positive Δ∈ is used. Moreover, there is also a report regarding a driving mode for performing display by means of vertically aligning a liquid crystal composition showing positive Δ∈ when voltage is not applied and applying a transverse electric field thereto. Accordingly, there is an increasing need for a liquid crystal composition showing positive Δ∈. Meanwhile, in all of driving modes, low-voltage driving, high-speed response, and a wide driving temperature range are required. That is, it is required that Δ∈ be positive and have a great absolute value, a viscosity (η) be low, and a nematic phase-isotropic liquid phase transition temperature (Tni) be high. Further, it is necessary to adjust Δn of the liquid crystal composition within an appropriate range according to a cell gap, by means of set Δn×d which is a product of Δn and the cell gap (d). In addition, when the liquid crystal display devices are applied to televisions and the like, high-speed responsiveness is emphasized, and accordingly, a liquid crystal composition having a low rotational viscosity (γ1) is required.
Regarding the constitution of liquid crystal compositions focusing on the high-speed responsiveness, for example, there is a disclosure about liquid crystal compositions using a combination of a liquid crystal compound which shows positive Δ∈ and corresponds to a compound represented by Formula (A-1) or (A-2) and a liquid crystal compound (B) showing neutral Δ∈. In these liquid crystal compositions, the liquid crystal compound showing positive Δ∈ has a —CF2O— structure, and the liquid crystal compound showing neutral Δ∈ has an alkenyl group. These characteristics are widely known in the field of such liquid crystal compositions (PTL 1 to 4).

Meanwhile, as the use of the liquid crystal display device becomes more diverse, there has been great changes in the use and the production method thereof. In order to address such changes, it is required to optimize the characteristics other than the conventionally known values of the basic physical properties. That is, for liquid crystal display devices using a liquid crystal composition, the VA mode, the IPS mode, and the like are widely used, and regarding the size, the supersized display devices that are equal to or larger than 50 inches have become commercialized and used. As the substrate size is enlarged, instead of the conventional vacuum fill process, One Drop Fill (ODF) process is mainly used as a method for filling a substrate with a liquid crystal composition. However, a problem that display quality deteriorates due to marks on composition from when the liquid crystal composition is dropped onto the substrate has been noticed. Moreover, in a liquid crystal display device production process performed by the ODF process, according to the size of the liquid crystal display device, liquid crystals for filling need to be dropped in an optimal amount. If the filling amount significantly deviates from the optimal value, the refractive index or driving electric field, which is designed beforehand, of the liquid crystal display device is thrown off balance, and this leads to display defectiveness such as formation of spots, contrast defectiveness, and the like. Particularly, the optimal amount of liquid crystals for filling small-sized liquid crystal display devices, which are frequently used in smart phones that are in vogue these days, is small. Therefore, it is difficult to control the deviation amount from the optimal value to be within a certain range. Consequently, in order to maintain a high yield of the liquid crystal display device, for example, the device needs to be influenced less by sudden pressure change or impact caused in a dropping apparatus during dropping of liquid crystals, and needs to have performance that makes it possible to stably and continuously drop liquid crystals over a long time.
As described so far, the liquid crystal composition used in an active matrix driving liquid crystal display device that is driven by a TFT device or the like is required to be developed, in consideration of the characteristics in which the device maintains properties or performances such as high-speed responsiveness that is required for a liquid crystal display device, has a high degree of specific resistance or voltage holding ratio that have been conventionally emphasized, and is stable with respect to external stimulation such as light or heat, as well as the production method of the liquid crystal display device.